1. Field of the Invention
The present invention relates to a rolling bearing assembly that may be employed in or for a vehicle transmission.
2. Description of Related Art
Within a vehicle transmission, a wide variety of substances or objects, such as wear debris from gears, may exist. To ensure protection against these potential contaminants, a conventional bearing assembly employed in a vehicle transmission may be equipped with a contact type sealing plate (i.e. seal member). Such a contact type seal member may seal a bearing space to prevent possible contaminants from entering the inside of the bearing assembly. However, a contact type seal member may generate a sealing torque. One of the barriers to improving the fuel economy of a vehicle may be how to reduce such mechanical loss.
Conventional techniques used to reduce mechanical loss may involve reduction of contact force that may be generated at a seal lip. For example, a shot peening process may be performed on a surface with which a contact-type seal lip comes in contact, to reduce the surface's maximum roughness Ry down to 2.5 μm or below. This may achieve reduction of a sealing torque caused by the operation of a seal lip (see the Patent Document 1 listed below).
[Patent Document 1] JP Laid-open Patent Publication No. 2007-107588
[Patent Document 2] JP Laid-open Patent Publication No. H08-296658